spotlight. The president pledged to shut down during his campaign. ABC's chief national correspondent Byron Pitts got a rare look inside. Reporter: Justice moves slowly at guantanamo bay. Of the 149 who remain inside the wires, some like alleged 9/11 architect will face trial. But many others, like the five Taliban commanders freed in exchange for Bowe bergdahl, were never charged. At this point, we're standing no more than ten feet away from the detainees. They can't see us. This glass we're seeing is one-sided. Inside one camp it's dark. We're asked to keep quiet. They're calling for the guard. So, you guys can't be seen. Reporter: We step back. We noticed when the guards went in they wore those protective shields to protect their faces. Shields protect from cocktails of urine and feces that have been hurled in their direction. A few minutes, afternoon prayer begins. And we're soon escorted out. 700 men have come through gitmo. Some say past allegations of waterboarding and hungry strikes have turned this place into a terrorist recruiters dream. These men are ghosts. They're not being held for who they are. They're being held for our idea of who they are. Reporter: The defense secretary has final sign-off on transfers. And the white house has been pressuring him to pick up the pace of transferring low-level detainees. National security adviser Susan rice reportedly asking last month for updates every two weeks." Commander of the joint detention center. How concerned should the American public, at some point, this place will close, they'll be transferred? As a private citizen, and a military officer, I think we need to be concerned about it. Reporter: Why? Once we transfer them to another country, we're obviously losing control over that. Reporter: Nearly half the men here have already been cleared to leave by an independent review panel, identified as, bodyguards to drivers. Waiting for Hagel's transfer order. The other, more dangerous detainees may need to be transferred to U.S. Prisons. You believe at some point, that some of the detainees at guantanamo bay will serve their time on U.S. Soil? Yes, I do. Reporter: I can hear some folks in congress saying, over my dead body. In addition to other issues with guantanamo, it is enormously expensive. Reporter: So, as the sun sets on gitmo, the dilemma -- which of these prisoners pose a continuing threat and where should they go? For "This week," Byron Pitts, ABC news, guantanamo bay. And the roundtable weighs in

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